2GB Memory RAM Upgrade for the Lenovo Thinkpad R61 Series, T60 Series, T61 Series, X60 Series and X61 Series Laptops (DDR2-667, PC2-5300, SODIMM) at Amazon.com
LENOVO THINKPAD R61 Intel Core 2 Duo 3GB RAM 160GB HDD WIFI LINUX MINT | eBay
2GB [1x2GB] Memory RAM Upgrade for the Lenovo ThinkPad R61, R61e, R61i Laptops | eBay
2GB RAM Memory for Lenovo ThinkPad R61 7742 Black Diamond Memory Module DDR2 SO-DIMM 200pin PC2-5300 667MHz Upgrade - Walmart.com